Wow, thanks for all the info!

I do like my current frame. It seems to fit me well, and it's in good shape (though there are a couple tiny rust spots I need to take care of). I don't like the saddle and haven't found a way to adjust it so that it doesn't feel like I'm constantly sliding forward. I know that's easy enough to fix. I also need to get a new headset. I have upright handlebars right now, and I am going to get dropped ones, and switch out my shifters (and probably brakes) while I'm at it.

I have taken some moderately long rides, and the biggest problem is the saddle issue. It's possible something else will come up once that's fixed...

I talked to a guy at a local bike shop when I got it tuned up a couple months ago. He said it was a really nice frame and said it could make a nice road bike. The shop I went to specializes in vintage road bikes, so I think it would not only be a good fit, but they also have lots of parts on hand and seem to be pretty reasonably priced.

It sounds like maybe my plan of action should be to fix up the one I've got now for this season and save my pennies and buy something new next year...